Rad City Chainring advice to increase top speed! Help Please!

ExPatBrit

Active Member
Which motor did you get? Stock or upgrade?
IMG_0526.jpg

Upgrade from the stock 350/500W motor to the real 750W watt from Bafang

You can just see the stock Rad Motor in the background of the pic
 

BKing

Active Member
Cool! So you have the torque of a geared motor plus a good top speed. To put that on a City would require a new wheel too right? Due to thickness of the motor.
 

ExPatBrit

Active Member
Cool! So you have the torque of a geared motor plus a good top speed. To put that on a City would require a new wheel too right? Due to thickness of the motor.

I have a Rover, 30 minutes work to switch . On a city with a freewheel the rear frame sizing is wrong.

Not an expert but with a city you need a MAC/ GMAC motor.

The new RAD mission has the smaller wheel and the geared hub but it's fixed gear.
 

Jim Mass

New Member
I already discussed this issue with my bike "Wrench master". I have a 2018 City Step-thru with the 46T chainring. Not big enough. You need a 52 T. Unfortunately for me I would have to modify the frame to get it to fit. The key is to replace the Step=thru model with the one featured if I can talk my wife into riding this one and I buy the model like yours after my upcoming hip replacement. Then change that to a 52 T.

At age almost 77 next month I ride for exercise, 20-25 miles per ride. Most of the time I'm in what I call exercise mode (PAS 1) in 6th to 7th gear, averaging 15-17mph on the flats. I want the higher chain ring so that there is peddle resistance and want to ride 5th and 6th gear saving 7th when I want more speed. I'm averaging 125 miles per month the last 18 months. Just turned 2,400 miles. I absolutely love the bike.
 
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nj1266

New Member
Region
USA
I already discussed this issue with my bike "Wrench master". I have a 2018 City Step-thru with the 46T chainring. Not big enough. You need a 52 T. Unfortunately for me I would have to modify the frame to get it to fit. The key is to replace the Step=thru model with the one featured if I can talk my wife into riding this one and I buy the model like yours after my upcoming hip replacement. Then change that to a 52 T.

At age almost 77 next month I ride for exercise, 20-25 miles per ride. Most of the time I'm in what I call exercise mode (PAS 1) in 6th to 7th gear, averaging 15-17mph on the flats. I want the higher chain ring so that there is peddle resistance and want to ride 5th and 6th gear saving 7th when I want more speed. I'm averaging 125 miles per month the last 18 months. Just turned 2,400 miles. I absolutely love the bike.
i Looked up the rad city step thru design and i can now see the problem. https://electricbikereview.com/rad-power-bikes/2018-radcity-step-thru/ What a dumb design? Why the hell did they place an additional metal buttress right above the chain ring. There must have been a better way to strengthen the chassis. I looked up the rear cassette and it is a 14-34 design. The 2020 has an 11-34 cassette. So all you have to do is call Rad Power and have them send you the 11-34 cassette and get your bike mechanic to install it.
 
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AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Jim, that 11 tooth freewheel is is available from Amazon if you like. You can get it 11-28, or if you prefer with granny gear, 11-34. I had one of the earlier 14t bikes, and my cadence was all done at maybe 15mph. The 11 tooth will let me stay up with the pedals until around 20mph

11-28

11-34
 

nj1266

New Member
Region
USA
Jim, that 11 tooth freewheel is is available from Amazon if you like. You can get it 11-28, or if you prefer with granny gear, 11-34. I had one of the earlier 14t bikes, and my cadence was all done at maybe 15mph. The 11 tooth will let me stay up with the pedals until around 20mph

11-28

11-34

I got the 11-28 and installed it on my Swagtron EB7+. It made a huge difference. I was able to maintain a cadence in top gear and mode 3. I couldn't do that with the lousy 14-28 gearing. I highly recommend the Drift Maniac 11-28. If you have a lot of hills to climb, then go with the 11-34.
 

irdeep

New Member
Region
USA
My 2020 Rad City is an awesome bike. But, for me, in the flat, I spend most of my time in 6th or 7th gear. Top speed around 24.5 mph, in PAS 0 or 1. I am wanting to increase the current chainring from 42 tooth, to maybe 44 or 46 tooth. Two issues I have found and need advice.
1) What is the size and measurement of the 2020 Rad City Chainring: BCD 130 - 42 tooth 5 bolt, BCD 140 -42 tooth 5 bolt or something else?
2) With the increase chainring to 44 tooth or 46 tooth, will I need a new, longer chain?
I have put three chaingring into my basket at Amazon, and have had to CXCL them because I'm unsure of the proper sizing of the chainring. A video on You tube shows a chainring upgrade on a 2018 Rad Rover, but it's clearly 4 bolt pattern.
And this video. Also for an earlier Rad Rover.
Thank You for the knowledge and advice.
I have the RadCity 4 and I got a 53T chainring with an integrated guard (the stock Rad guard was too small). The product I ordered on Amazon is here: https://smile.amazon.com/gp/product/B08338WJFJ/ref=ppx_yo_dt_b_asin_title_o05_s00 - I had a shop put it on, they needed to add some links to the chain and they also had to use smaller chainring bolts because the stock rad bolts were much too long. I think it looks great and it solved my freewheeling issue.
 

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